A caça comercial de grandes baleias, os emalhes de pequenos odontocetos e a poluição são alguns dos fatores que contribuíram para a redução de muitas populações de cetáceos. No entanto, enquanto algumas populações de misticetos se recuperaram mais rapidamente do que outras, os odontocetos foram menos resilientes. Os motivos que levaram algumas populações de misticetos a se recuperarem mais rápido, enquanto outras ainda se recuperam, não são muito bem compreendidos, da mesma forma ainda não se compreende o motivo pelo qual os odontocetos se recuperam mais lentamente. Nesse sentido, o estudo do sucesso reprodutivo pode auxiliar a elucidar os principais fatores que interferem na recuperação dessas espécies. O objetivo da presente dissertação foi levantar dados da literatura científica que indicassem quais são os principais fatores que influenciam o sucesso reprodutivo, causando acréscimo ou decréscimo da taxa de reprodução dos cetáceos de vida-livre, e apresentar os métodos mais utilizados nesse tipo de estudo. Para tanto, foram considerados os artigos científicos publicados a partir de 2000. Nos cetáceos o cuidado parental é exclusivamente materno, portanto, os estudos sobre o sucesso reprodutivo são baseados em dados de observações em campo de fêmeas com filhote, usando a foto-identificação, as análises de parentesco, as imagens de ultrassons e as dosagens hormonais. Comparando populações da mesma espécie, algumas possuem machos com variação no sucesso reprodutivo, ou seja, machos que produzem mais descendentes do que outros, e existem populações que o sucesso reprodutivo não varia, todos os machos geram quase o mesmo número de descendentes. De acordo com a teoria da seleção sexual de Darwin, a seleção das características vantajosas dos parceiros sexuais explica a variação do sucesso reprodutivo. Essas características podem ser comportamentais, morfológicas ou fisiológicas. Tanto em odontocetos quanto em misticetos, quando há variação no número de descentes gerados, os machos mais velhos parecem possuir vantagens sobre os mais novos. Alguns autores sugerem que isso ocorre devido ao desenvolvimento físico e da concentração mais alta de hormônios andrógenos nos machos mais velhos, outros sugerem que é devido à experiência. Com relação às estratégias reprodutivas, alguns odontocetos além de utilizarem estratégias que sejam favorecidas por conta de seus atributos corporais, o sucesso reprodutivo é também favorecido por formações de grupos sociais estáveis, os quais muitas vezes são constituídos por indivíduos com algum grau de parentesco. Já os misticetos utilizam mais as estratégias reprodutivas que são favorecidas em função de seus atributos corporais. Finalmente, alguns fatores como o aumento da temperatura da superfície do mar e a diminuição da disponibilidade de presas impactam o crescimento populacional de algumas espécies de misticetos; e a poluição tem diminuído o sucesso reprodutivo das fêmeas, sobretudo dos odontocetos que vivem próximos à regiões costeiras. / The commercial whaling, small odontocetes bycatch, and pollution are some of the factors contributing to the decline of many cetacean populations. However, while some populations of mysticetes recovered faster than others, odontocetes were less resilient. The reasons that led some populations to recover faster while others are still recovering are not well understood, likewise do not understand yet why the odontocetes appear to recover more slowly. The study of reproductive success can help to elucidate the main factors that interfere with the recovery of these species. The aim of the present dissertation was to collect data of scientific literature that could indicate the main factors influencing reproductive success, causing an increase or decrease of free-ranging cetaceans reproductive rate, and present the most used methods in this type of study. Therefore, the scientific articles published since 2000 were considered. In cetaceans, parental care is exclusively maternal, so reproductive success studies are based on data from field observations of females with calves, using photo-identification, kinship analysis, ultrasound imaging, and hormonal dosages. Comparing cetaceans populations of the same species, some populations have males with variation in reproductive success (i.e. males that produce more offspring than others), and there are populations that reproductive success does not vary (i.e. all males generate almost the same number of offspring). According to Darwins theory of sexual selection, the mate selection with advantageous characteristics explains the reproductive success variation. These characteristics can be behavioral, morphological or physiological. In odontocetes and mysticetes, when there is variation in the number of descendants generated, the older males seem to have advantages over the younger. Some authors suggest that this occurs because of the physical development and the highest concentration of androgen hormones in older males, other authors suggest that is due to the experience. Regarding reproductive strategies, some odontocetes besides using strategies that are favored since their physical attributes seem to have reproductive success favored by a formation of stable social groups, which often are made up of individuals with some degree of kinship. While the mysticetes seem to use more reproductive strategies that are favored according to their corporal attributes. Finally, factors such as the increase in sea surface temperature, and the decrease reduction of prey availability, impact the population growth of some mysticetes; and the pollution has decreased the female reproductive success, especially in odontocetes that living close to the coastal regions.

A caça comercial de grandes baleias, os emalhes de pequenos odontocetos e a poluição são alguns dos fatores que contribuíram para a redução de muitas populações de cetáceos. No entanto, enquanto algumas populações de misticetos se recuperaram mais rapidamente do que outras, os odontocetos foram menos resilientes. Os motivos que levaram algumas populações de misticetos a se recuperarem mais rápido, enquanto outras ainda se recuperam, não são muito bem compreendidos, da mesma forma ainda não se compreende o motivo pelo qual os odontocetos se recuperam mais lentamente. Nesse sentido, o estudo do sucesso reprodutivo pode auxiliar a elucidar os principais fatores que interferem na recuperação dessas espécies. O objetivo da presente dissertação foi levantar dados da literatura científica que indicassem quais são os principais fatores que influenciam o sucesso reprodutivo, causando acréscimo ou decréscimo da taxa de reprodução dos cetáceos de vida-livre, e apresentar os métodos mais utilizados nesse tipo de estudo. Para tanto, foram considerados os artigos científicos publicados a partir de 2000. Nos cetáceos o cuidado parental é exclusivamente materno, portanto, os estudos sobre o sucesso reprodutivo são baseados em dados de observações em campo de fêmeas com filhote, usando a foto-identificação, as análises de parentesco, as imagens de ultrassons e as dosagens hormonais. Comparando populações da mesma espécie, algumas possuem machos com variação no sucesso reprodutivo, ou seja, machos que produzem mais descendentes do que outros, e existem populações que o sucesso reprodutivo não varia, todos os machos geram quase o mesmo número de descendentes. De acordo com a teoria da seleção sexual de Darwin, a seleção das características vantajosas dos parceiros sexuais explica a variação do sucesso reprodutivo. Essas características podem ser comportamentais, morfológicas ou fisiológicas. Tanto em odontocetos quanto em misticetos, quando há variação no número de descentes gerados, os machos mais velhos parecem possuir vantagens sobre os mais novos. Alguns autores sugerem que isso ocorre devido ao desenvolvimento físico e da concentração mais alta de hormônios andrógenos nos machos mais velhos, outros sugerem que é devido à experiência. Com relação às estratégias reprodutivas, alguns odontocetos além de utilizarem estratégias que sejam favorecidas por conta de seus atributos corporais, o sucesso reprodutivo é também favorecido por formações de grupos sociais estáveis, os quais muitas vezes são constituídos por indivíduos com algum grau de parentesco. Já os misticetos utilizam mais as estratégias reprodutivas que são favorecidas em função de seus atributos corporais. Finalmente, alguns fatores como o aumento da temperatura da superfície do mar e a diminuição da disponibilidade de presas impactam o crescimento populacional de algumas espécies de misticetos; e a poluição tem diminuído o sucesso reprodutivo das fêmeas, sobretudo dos odontocetos que vivem próximos à regiões costeiras. / The commercial whaling, small odontocetes bycatch, and pollution are some of the factors contributing to the decline of many cetacean populations. However, while some populations of mysticetes recovered faster than others, odontocetes were less resilient. The reasons that led some populations to recover faster while others are still recovering are not well understood, likewise do not understand yet why the odontocetes appear to recover more slowly. The study of reproductive success can help to elucidate the main factors that interfere with the recovery of these species. The aim of the present dissertation was to collect data of scientific literature that could indicate the main factors influencing reproductive success, causing an increase or decrease of free-ranging cetaceans reproductive rate, and present the most used methods in this type of study. Therefore, the scientific articles published since 2000 were considered. In cetaceans, parental care is exclusively maternal, so reproductive success studies are based on data from field observations of females with calves, using photo-identification, kinship analysis, ultrasound imaging, and hormonal dosages. Comparing cetaceans populations of the same species, some populations have males with variation in reproductive success (i.e. males that produce more offspring than others), and there are populations that reproductive success does not vary (i.e. all males generate almost the same number of offspring). According to Darwins theory of sexual selection, the mate selection with advantageous characteristics explains the reproductive success variation. These characteristics can be behavioral, morphological or physiological. In odontocetes and mysticetes, when there is variation in the number of descendants generated, the older males seem to have advantages over the younger. Some authors suggest that this occurs because of the physical development and the highest concentration of androgen hormones in older males, other authors suggest that is due to the experience. Regarding reproductive strategies, some odontocetes besides using strategies that are favored since their physical attributes seem to have reproductive success favored by a formation of stable social groups, which often are made up of individuals with some degree of kinship. While the mysticetes seem to use more reproductive strategies that are favored according to their corporal attributes. Finally, factors such as the increase in sea surface temperature, and the decrease reduction of prey availability, impact the population growth of some mysticetes; and the pollution has decreased the female reproductive success, especially in odontocetes that living close to the coastal regions.

The diploma thesis dealt with the analysis, and evaluation of dairy performance and its correlation with reproductive rates of Holstein cattle. Milk cows which were kept in Měcholupy agricultural, Inc., Předslav were analyzed between 2013 - 2015. Th ecompany is located in the foothills of the Bohemian Forest (Šumava). It breeds cattle for milk as well as meat, and pigs. The company management is committed to achieve good levels of milk production. It pays constant attention to this issue, so the average performance has risen since 2013 from 8 726 kilograms of milk to 9 093 kg of milk per cow in 2015. Cows on the 4th and higher lactation reached the highest performance in 2015 9 649 kg of milk. As for the European Union who abolished milk quotas in 2015 and the situation on the milk market is still complicated by banning exports of milk powder to Russia (Russian annexation of the Crimea), the management´s effort has been to produce milk at the lowest possible cost. They keep trying to limit culling as much as possible, so that they solve the problem of mastitis and reproduction at the highest level. Each cow which is treated has an individual approach, as well as the animal husbandry has specific requirements for animal breeding company in terms of quality seed. The results showed that milk cows with other health problems were eliminated the most (38.6% per year from 2013 to 2015) and also the ones with metabolism disorders and problems with hooves. The mastitis issue is dealt with very effectively, so that it is not one of the major problems of the herd (7.24 % for 2013 -2015). Management seeks to eliminate the problem milk cow in the lowest age and conversely on contrary if the animal is healthy, they try to keep it in the herd as long as possible, because such an animal has the greatest economic effect. Reproductive rateis not too satisfactory, but the management has no interest in hormonal control of reproduction. Active search of rutting cows is preferred by nursing staff. They cooperate actively with animal breeders and require a delivery of the insemination doses according to their requirements for each for each cow

I used a theoretical model to determine the conditions under which Cactoblastis cactorum populations would be expected to experience positive population growth. Results from simulations suggest that host species richness, host quality, and the C. cactorum death rate interact to determine the probability of C. cactorum positive population growth. I also studied the influence of host diversity empirically. Cactoblastis cactorum prevalence was significantly higher when O. stricta was present in the community. Also, higher species richness within host assemblages led to a higher prevalence of infestation than in single-species host assemblages. Finally, I explored cooccurrence patterns of native cactuseeding insects in an effort to document the impact of C. cactorum to native insect assemblages. The presence of C. cactorum in a community did not appear to affect the structure of native cactuseeding insect assemblages.

Knowledge of offspring production (recruitment) is fundamental to understanding and forecasting the dynamics of a population. In this thesis, I focus on two demographic characteristics of fish stocks that are important to recruitment: population density and age structure. First, populations produce more recruits at low density, but quantifying this response has proven difficult. Using data from hundreds of populations of walleye (Sander vitreus), an economically important freshwater fish, I demonstrate that the growing-degree-day metric (a temperature index) is better than age at explaining variation in density-dependent growth and maturity both within and among populations. I then incorporate multi-lake measures of density-dependent life history change into a temperature-based biphasic model of growth and reproduction to predict sustainable rates of mortality for walleye throughout most of their range. Second, the age (or size) structure of a population may also affect recruitment because of positive effects of maternal age on offspring production and survival; however, evidence for these ‘maternal influences’ on recruitment is limited. Using both an analytical model and a meta-analysis of stock-recruitment data from 25 species of exploited marine fish, I show that (i) maximum reproductive rate increased with the mean age of adults in a population, and (ii) the importance of age structure increased with a species’ longevity. I then demonstrate a similar effect of maternal influences on reproductive rate in a detailed study of Lake Erie walleye. By highlighting the importance of fisheries-induced demographic change to recruitment, this thesis provides insight into past and present failures. However, it also demonstrates clearly the benefits of proactive management strategies that (i) identify and respect the limits of exploitation, (ii) protect from exploitation reproductively valuable individuals—principles that apply generally to any freshwater, marine, or terrestrial species that is of recreational, commercial, or conservation value.

Knowledge of offspring production (recruitment) is fundamental to understanding and forecasting the dynamics of a population. In this thesis, I focus on two demographic characteristics of fish stocks that are important to recruitment: population density and age structure. First, populations produce more recruits at low density, but quantifying this response has proven difficult. Using data from hundreds of populations of walleye (Sander vitreus), an economically important freshwater fish, I demonstrate that the growing-degree-day metric (a temperature index) is better than age at explaining variation in density-dependent growth and maturity both within and among populations. I then incorporate multi-lake measures of density-dependent life history change into a temperature-based biphasic model of growth and reproduction to predict sustainable rates of mortality for walleye throughout most of their range. Second, the age (or size) structure of a population may also affect recruitment because of positive effects of maternal age on offspring production and survival; however, evidence for these ‘maternal influences’ on recruitment is limited. Using both an analytical model and a meta-analysis of stock-recruitment data from 25 species of exploited marine fish, I show that (i) maximum reproductive rate increased with the mean age of adults in a population, and (ii) the importance of age structure increased with a species’ longevity. I then demonstrate a similar effect of maternal influences on reproductive rate in a detailed study of Lake Erie walleye. By highlighting the importance of fisheries-induced demographic change to recruitment, this thesis provides insight into past and present failures. However, it also demonstrates clearly the benefits of proactive management strategies that (i) identify and respect the limits of exploitation, (ii) protect from exploitation reproductively valuable individuals—principles that apply generally to any freshwater, marine, or terrestrial species that is of recreational, commercial, or conservation value.